Thousands of words have been written about the new ground broken by director Robert Zemeckis and his crew in the making of The Polar Express.

More than 500 visual-effects specialists developed a process called "performance capture," which allowed animators to digitally "wrap" bodies around data provided by sensors on the performers' skin.

This allows Tom Hanks to play five roles and to put his characters in places impossible to go except by animation and imagination.

But Chris Van Allsburg's book, which has become a holiday classic since it was published 19 years ago, is more about heart and belief and magic than it is about reality. And it's only 29 pages long, 80 percent of which is illustration.

So the big questions are: Does expanding the story into a 97-minute film work, and does "performance capture" enhance the end product? The answer to the first is yes. The answer to the second is maybe.

I suspect that The Polar Express will make lots of money and

sell a gazillion DVDs. The movie certainly deserves a place on

the shelf with other holiday favorites.

But that s because of the story, which was expanded by

Zemeckis and William Broyles, Jr., not necessarily the special

effects. The same movie could have been made by a team of

animators without the benefi t of digital sensors, electronic whatsis,

and computerized thingys.

Yes, there are limits to animation, especially in humorous sequences.

It s tough to maintain a fi ne line between comedy and cartoon. But there look to be limits to performance capture, as well. More than once, it seems as if the characters are trying to express emotions through Botox-injected faces.

On the other hand, Hanks is so darn likable, it makes sense

to use him. Putting him into fi ve roles quintuples the fi lm s

chance of success.

He plays the Boy, the Conductor, the Hobo, the Boy s father,

and Santa Claus. He looks like himself as the Conductor, but

you can spot his features in the other characters, too, changed

just enough so as not to be disconcerting or confusing. (Actually,

the Hobo looks like a cross between Hanks and Dick Van

Dyke.)

There are at least four main characters who aren t in the book:

the Hobo, the Girl, the Lonely Boy, and the Know-It-All Boy.

As in the book, most of the characters are given labels rather

than names. This is done, I suspect, to allow young viewers to

identify with one or the other of the characters and to make the

story more universal.

(Here s a conundrum: If the fi lmmakers want to make the

characters available to every viewer, why allow some of them

to be identifi able as Hanks?)

The book s plot is simple.

A boy fi ghts to believe in the magic of Christmas even as his

friends insist that there is no Santa Claus. A magic train stops

outside the house on Christmas Eve, after everyone except the

boy is asleep, and takes him to the North Pole, where he is given

a gift that helps him ignore the cynics.

In The Polar Express movie, the tone changes.

The Boy wants to believe, but he has become a skeptic. He

needs proof. He needs to see for himself.

When a magic train stops outside his house, he almost ignores

the Conductor s invitation, but at the last minute, he hops aboard

and joins a bunch of children, all of whom are searching for an answer.

Maybe it s not an answer as to whether Santa exists, but an

answer to a question that nags at each individual soul.

The Boy keeps to himself on the train, despite the friendly

overtures of the Girl in the seat across the aisle. And he watches

as the train stops again and the Conductor invites another boy

aboard, this one from a shabby house with no sign of Christmas

in its windows.

This boy does turn down the Conductor, and the train pulls

away. Then, like the fi rst Boy, the lad in the yard has second

thoughts and begins running after the train. But it s too late.

The Boy recognizes something of himself in the lad left behind, so he pulls the emergency brake, bringing the train to a screeching stop. The lad jumps aboard, looks at the lights and laughter in the children s car, and chooses to sit in a dimly lit empty car. It is as if

he feels he does not deserve to be with the others.

Worse than that, it brings the Boy to the unhappy attention

of the Conductor.

Even though there are many characters and situations that

don t show up in the book, the movie is faithful to Allsburg s

story. For example, there is a scene in the book in which

wolves watch the train chug through a thick forest. In the

movie, the wolves have a key role in a sequence involving

a missing train ticket, which leads to another sequence

in which the Boy meets the Hobo, sitting at a campfi re

atop one of the railroad cars.

It is the Hobo who helps the Boy to understand that although

seeing is believing is generally true, sometimes it s tough to believe in things you do see. And if that s the case, why should it be any more diffi cult to believe in something you don t see?

Allsburg won a Caldecott Medal for the illustrations in

his book, and it wouldn t be surprising if Zemeckis took

home a multitude of awards for his special effects.

But neither would be worth a dime without Allsburg s

strong story and Zemeckis ability to expand on it.

Sure, the special effects are interesting, but the magic of

imagination and belief are even better.

And that s something that no digital sensor can manufacture.

First Published November 10, 2004, 1:12 p.m.